Ordering Recommendation

Preferred diagnostic or predictive test for familial adenomatous polyposis and MUTYH-associated polyposis.

Mnemonic
FAP Panel
Methodology

Polymerase Chain Reaction/Sequencing/Multiplex Ligation-dependent Probe Amplification

Performed

Varies

Reported

21-28 days

New York DOH Approval Status
Specimens from New York clients will be sent out to a New York DOH approved laboratory, if possible.
Specimen Required
Patient Preparation
Collect

Lavender (K2EDTA), Pink (K2EDTA), or Yellow (ACD Solution A or B).

Specimen Preparation

Transport 3 mL whole blood. (Min: 2 mL)

Storage/Transport Temperature

Refrigerated.

Unacceptable Conditions
Remarks
Stability

Ambient: 1 week; Refrigerated: 1 month; Frozen: 6 months

Reference Interval
Interpretive Data

Background Information for Familial Adenomatous Polyposis Panel: (APC) Sequencing and Deletion/Duplication, (MUTYH) 2 Mutations:

Characteristics of APC-associated Polyposis:
Familial Adenomatous Polyposis (FAP): Development of hundreds to thousands of adenomatous colonic polyps beginning in early adolescence; lifetime risk for cancer is 100 percent. Additional findings may include dental anomalies, polyps of the gastric fundus and duodenum, and congenital hypertrophy of the retinal pigment epithelium (CHRPE).
Attenuated FAP: Fewer colonic adenomatous polyps (average of 30), which are more proximally located and cancer generally occurs at a later age; lifetime risk for cancer is 70 percent.
Gardner syndrome: Multiple colonic adenomatous polyps along with osteomas, desmoid tumors, and soft tissue tumors.
Incidence:
  Less than 1 percent of colorectal cancer cases.
Inheritance:
  Autosomal dominant.
Penetrance:
  Greater than 99 percent in untreated individuals.
Causes:
  Pathogenic APC gene mutations.
Clinical Sensitivity:
Approximately 95 percent for classic FAP and less than 30 percent for attenuated FAP.
Methodology:
Bidirectional sequencing of the APC coding region and intron-exon boundaries.  Multiplex ligation-dependent probe amplification (MLPA) to detect large APC coding region deletions or duplications. 
Analytical Sensitivity and Specificity:
99 percent.
Limitations
: Diagnostic errors can occur due to rare sequence variations. APC regulatory region and deep intronic mutations will not be detected. Deletion/duplication breakpoints will not be determined. This assay is not designed to detect somatic variants associated with malignancy. Interpretation of this test result may be impacted if the patient has had an allogeneic stem cell transplantation.

Characteristics of MUTYH-associated Polyposis (MAP):
Development of colonic polyps (10-100) with the age of diagnosis occurring in the third decade or older.
Incidence:
  Less than 1 percent of colorectal cancer cases.
Inheritance:
Autosomal recessive.
Penetrance:
Greater than 99 percent in untreated individuals.
Causes:
Pathogenic biallelic MUTYH gene mutations.
Clinical Sensitivity:
85 percent of MUTYH mutations in Caucasians.
Methodology:
Targeted testing for the MUTYH mutations c.494A>G(Y165C) and c.1145G>A (G382D) by PCR and bidirectional sequencing.
Analytical Sensitivity and Specificity:
99 percent.
Limitations:
Diagnostic errors can occur due to rare sequence variations. Mutations in the MUTYH gene, other than Y165C and G382D, are not evaluated.

Compliance Statement C: For human genetic inheritable conditions and mutations. This test was developed and its performance characteristics determined by ARUP Laboratories. The U. S. Food and Drug Administration has not approved or cleared this test; however, FDA clearance or approval is not currently required for clinical use. The results are not intended to be used as the sole means for clinical diagnosis or patient management decisions.

Counseling and informed consent are recommended for genetic testing. Consent forms are available online.

Note
Hotline History
N/A
CPT Codes

81201; 81203; 81401

Components
Component Test Code* Component Chart Name LOINC
2004916 FAP Panel Specimen
2004917 FAP Panel Interp
* Component test codes cannot be used to order tests. The information provided here is not sufficient for interface builds; for a complete test mix, please click the sidebar link to access the Interface Map.
Aliases
  • APC-Associated Polyposis
  • Attenuated FAP
  • Gardner Syndrome
  • Turcot Syndrome
Familial Adenomatous Polyposis Panel: (APC) Sequencing and Deletion/Duplication, (MUTYH) 2 Mutations